What's the noun for cranker? Here's the word you're looking for.
crank
A bent piece of an axle or shaft, or an attached arm perpendicular, or nearly so, to the end of a shaft or wheel, used to impart a rotation to a wheel or other mechanical device; also used to change circular into reciprocating motion, or reciprocating into circular motion.(Can we add an example for this sense?)
The act of converting power into motion, by turning a crankshaft.
(archaic) Any bend, turn, or winding, as of a passage.
“These are players who can qualify both as crankers and power strokers.”
“Be careful now, for auto crankers sometimes get broken arms. You take a firm grip on the crank, pull the choke wire and whirl the crank like the very devil.”